Length 14.5 mm. North Yorkshire. September 2014. (leg. Paula Lightfoot).
Properiostracum has consistency like collagen, may become loose and easily rubbed off if animal loses condition in captivity.

Left: live animal in good condition with greenish-cream and vibrant brick-red/orange partly within properiostracum.
Right: same animal, still alive but in poorer condition and properiostracum lost; has diminished vibrancy.

See image 3Tr 03 Boreochiton ruber for further colour loss after death.

KEY ID FEATURES and similar species at: 01 Boreochiton ruber. Length 12mm. North Yorkshire. September 2014. (leg. Paula Lightfoot).